Novel green production of natural-like vanilla extract from curcuminoids

The demand for natural vanilla extract, and vanillin in particular, by far exceeds the current production, as both the cultivation of vanilla beans and the extraction of vanillin are laborious. For this purpose, most vanillin used today is produced synthetically, contrary to the general trend toward bio-based products. The present study deals with the synthesis of nature-based vanillin, starting with the more accessible rhizomes of the plant Curcuma longa. Besides vanillin, vanillic acid and p-hydroxybenzaldehyde are synthesized that way, which are also found in the natural vanilla bean. The extraction of the curcuminoids and, finally, their conversion to the flavors are performed using visible light and food-grade chemicals only. A binary mixture of ethanol and triacetin, as well as a surfactant-free microemulsion consisting of water, ethanol, and triacetin, are investigated in this context. The results exceed the literature values for Soxhlet extraction of vanilla beans by a factor > 7.

Automated summary

The demand for natural vanilla extract, specifically vanillin, is much higher than current production due to the labor-intensive process of vanilla bean cultivation and vanillin extraction. To meet this demand, most vanillin used today is synthetically produced, contrary to the trend towards bio-based products. This study focuses on synthesizing nature-based vanillin from the more accessible rhizomes of Curcuma longa, which also produces vanillic acid and p-hydroxybenzaldehyde found in natural vanilla beans. Visible light and food-grade chemicals are utilized for the extraction and conversion of curcuminoids to flavors. The use of a binary mixture of ethanol and triacetin, as well as a surfactant-free microemulsion consisting of water, ethanol, and triacetin, achieves extraction results exceeding those reported in the literature for Soxhlet extraction of vanilla beans by a factor of more than 7.